Stanford University Responds to my questions:

Here's a the first organization that I got to respond to my questionnaire found here: Stanford is a TREMENDOUS asset to this site and all that they do!

The Responses:

Here's some questions that I want answered:

1. What if a man/woman 45 years of age came into your ER department complaining of chest pains. What would be the first things you would do to begin to rule out the possibility of an AorticDissection?

Obviously ER physicians or primary care providers have to be knowledgeable about a multitude of disease processes.  Whenever someone presents with chest pain, you have to rule out the bad things first.  This is based on statistical bell curves and probability of a certain disease process.  A 45 year old male will be at greater risk of an MI (myocardial infarction/heart attack) than a 45 year old female.  With that being said, a 45 year old, obese, diabetic, female with hypertension and a significant smoking habit will be at a greater risk for an MI than a 45 year old otherwise healthy male.  With all that being said, the first thing I would do to rule out a dissection would be to weigh the odds that someone is at risk for a dissection or MI.  From that point, the history and physical exam will be the first and most important tool for the primary care provider.  If you listen to your patient and/or the historian, they will tell you what is wrong with them.  The clues are in the history.  The confirmation is in the physical examination.  The problem is that a lot of care providers do not have the time for an “adequate” H/P and they jump to different diagnostic algorithms without listening to the situation or patient.  The fundamental reason for this and possible solutions are way beyond the scope of what you are looking for though.

In medicine as well as logic there is a rule called Occam’s Razor.  This essentially means that the most simple answer or most obvious answer that fits the most variables is the answer, no matter how improbable.  If it walks like a duck and talks like a duck, it’s probably a duck.  If you hear hoof beats, it’s probably a horse and not a zebra…unless you are in an area heavily populated by zebras.  As a care provider you have to get an idea if the patient is at risk for an MI or dissection.  From there, the history will either confirm or contradict the first impression.  If it contradicts your initial assessment, you must investigate further and broaden your “what ifs”.  After that, the treatment protocols are in place for medications (if their BP is high then control it with beta blockers if they are patient category X or with ACEIs if they are patient category Y [meaning with concomitant disease processes], treat pain with morphine, etc…) as well as procedures to be ordered such as labs (CBC, Chem panels, troponins, Cks [both are markers of tissue damage that are noticeable at different times], and diagnostic studies such as an EKG, echocardiogram, chest Xray, CT, or a CTA.

2. Is there a check list that you would use to differentiate from these? 

Yes and No.  The presentation in combination with the history and physical exam will provide you with a mental checklist but this is formulated by each practitioner based upon their knowledge and experiences. 

3. How would you be able to rule out that it was not a heart attack? 

If the patient is a 45 year old male with a history of high lipids, exertional chest pain, high blood pressure, tachycardia, high or low blood pressure, diaphoretic, with pain raditating in specific patterns, with classic or suspicious EKG findings, and his cardiac markers are abnormal, then I would think that it was probably a heart attack .  If the patient is a 45 year old otherwise healthy male with a remote history of a murmur, chest and back pain of a tearing quality, with absent femoral pulses and a family history of early unexplained deaths, then I would think that it was more than likely an aortic dissection, with the caveat that type A dissections can shear off or cause obstruction of a coronary artery causing myocardial damage.  This is essentially a heart attack caused by a type A aortic dissection and is probably part of the reason why a type A aortic dissection is so lethal.

4. How would you rule out that it was not a pulmonary embolism?

                This would go back to the presentation and history and physical examination.  PE patients have a plethora of presentations and symptomatology so they are particularly perplexing and PE should be considered in any patient presenting with CP or dyspnea.  Any of the above presentations in conjunction with sudden chest wall pain without a good history of trauma or strain to the area is particularly worrisome for a PE.  The only real way to rule out a PE in most cases is to get a multidector computed tomographic angiogram (MDCTA or CTA) to look at the pulmonary vessels.  This is the current diagnostic test of choice and the criterion for ruling in or ruling out a PE.  Other studies such as V/Q lung scans can also help rule in or rule out a PE if high resolution CTAs are unavailable.

5. Would there be clues like, different BP readings that you detect that might start you thinking down the possible AD path? Intense Back pain between shoulders? Numbness in limbs?

                Yes.  In addition to the clues gathered in the history and other clues in the subjective data (labs etc…), any discrepancy between upper and lower extremity pulses or any discrepancy between one side or the other side’s pulses would be a red flag.  This includes any numbness or paresthesias in any different pattern of upper verses lower or right verses left.  These types of symptoms would be more specific to an AD than intense back or intra-scapular pain (as that could represent far more diagnostic possibilities).  Any of these symptoms in addition to the previously mentioned presentation +/- the patient history would be a clue to an aortic dissection.

6. Would you act differently if the patient or loved one with them said you had a history of ADs in the family? Would you go to the CT scan immediately versus still trying to determine if it was a Heart Attack?

                Yes and Yes as aortic dissections, especially in a younger person can be linked genetically or in familial clusters.  If the patient is older and the possibility of atherosclerotic causes of an aortic aneurysm +/- dissection increase, then it would not be as significant.  However, a TTE (transthoracic echocardiogram) in the hands of an experienced sonographer can be an invaluable tool as well.  There are many different ways to view the aortic dissection flap via TTE and this can serve as a quick, easy, and financially soluble solution in an emergency situation.  Of course, not all dissection flaps are visible on TTE because of their location, morphology, or because of the patients anatomy; however, it can be a useful tool that should be included in your workup. 

7. Would there be a particular blood test such as a D-Dimer that you would run? What if it did come back high for a Pulmonary Embolism? Would  you order a CT right away?

                Yes.  The laboratory reports can be especially important.  If the D-dimer is high or marginal, then the current algorithm says yes-get a CTA.  If it is low, then a CTA is not warranted.  If Ck, CkMB, and/or troponins are abnormal in the presence of the CP presentation, then yes-an MI is likely.  If the creatinine or liver functions are abnormal in the previous presentation, then I would think that a dissection is likely (the dissection flap can occlude or shear off different vessels and cause different constellations of organ malfunction/damage) and would head for the CTA.

8. Do you feel that you have had adequate training on the subject of Aortic Dissections to be able to properly detect it if it was your loved one you were working on?


9. What gives you the "green" light to order a CT scan as you since your patient might be suffering from an ascending aortic dissection?

                Any of the above mentioned scenarios in addition to the number one tool in a clinician’s tool box, clinical judgment!  Intuition, experience, knowledge, and praxis all lead to more accurate clinical judgment.  If a care provider has treated a patient for an MI and it ended up being an aortic dissection, they almost always will include that work-up and possibility in the next CP presentation.  Care providers are human and act based on our knowledge influenced by our experience.  See the aforementioned analogy-if I lived in Montana and heard hoof beats, I would think it was a horse.  But if I moved to Zimbabwe or was on a mission trip, I would amend that based on the knowledge and experience of seeing zebras or any other hoofed animal in that location.  All of this is part of clinical judgment: knowledge in the presence of experience and praxis (action based on critical thinking and analysis of a situation).

10. How often do you get refresher course on the subject? Who provides them? How many AD's have you detected before? Did you use that check list as mentioned before? Have you changed your procedures on the ability to detect these based on what you have learned in the past?

                I am by training a Family Nurse Practitioner and nationally certified by the American Association of Nurse Practitioners.  I am currently the Nurse Practitioner for the Thoracic Aortic Surgery Unit at Stanford Hospital and Clinics, where I work for Doctors Craig Miller and Scott Mitchell.  I am responsible for working up our elective cases in the outpatient setting, meaning I review CTAs, echos, caths, and records and put into place the patient care plan.  I do not see emergency cases in the ER at Stanford.  However, I also work per diem as an NP in several urgent care centers around the bay area and we often get patients with chest pain.  I attend multiple conferences, symposia, or lectures annually to continually educate myself.  These are normally offered through professional organizations such as the STS, AATS, or AANP and often co-sponsored by finances from industry leaders.

Michael Sheehan

Nurse Practitioner for Thoracic Aortic Surgery

Stanford University Medical Center

300 Pasteur Drive

2nd Floor, Falk Building

Stanford, CA 94305-5407

PH:  650-725-0524

FX:  650-725-3846

"to cure-rarely, to treat-often, to care-always" 
Phone: 206-550-7957

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